Acquisition, Dispositions, Goodwill and Other Intangible Assets (Goodwill) (Details) $ in Millions	6 Months Ended
	Jun. 30, 2019 USD ($)
Goodwill [Line Items]
Goodwill - Beginning Balance	$ 48,112
Goodwill Resulting from Business Combinations	263
Goodwill - Foreign Currency Translation and Other	(17)
Goodwill - Ending Balance	48,358
Otis [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	1,688
Goodwill Resulting from Business Combinations	7
Goodwill - Foreign Currency Translation and Other	(16)
Goodwill - Ending Balance	1,679
Carrier [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	9,835
Goodwill Resulting from Business Combinations	1
Goodwill - Foreign Currency Translation and Other	3
Goodwill - Ending Balance	9,839
Pratt & Whitney [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	1,567
Goodwill Resulting from Business Combinations	0
Goodwill - Foreign Currency Translation and Other	(4)
Goodwill - Ending Balance	1,563
Collins Aerospace Systems [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	35,001
Goodwill Resulting from Business Combinations	255
Goodwill - Foreign Currency Translation and Other	0
Goodwill - Ending Balance	35,256
Total Segments [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	48,091
Goodwill Resulting from Business Combinations	263
Goodwill - Foreign Currency Translation and Other	(17)
Goodwill - Ending Balance	48,337
Eliminations and other [Member]
Goodwill [Line Items]
Goodwill - Beginning Balance	21
Goodwill Resulting from Business Combinations	0
Goodwill - Foreign Currency Translation and Other	0
Goodwill - Ending Balance	21
Customer relationships and other [Member]
Goodwill [Line Items]
Goodwill, Purchase Accounting Adjustments	$ 100